P743 Right ventricular function is important for exercise capacity in patients at risk of heart failure

Background and Purpose

It is important to evaluate exercise capacity to detect the development of heart failure (HF) in patients with heart disease. The pathology of exercise capacity is multi-factorial, and cardiac function is recognized as one of the most important determinants. However, the correlation between right ventricular (RV) function and exercise capacity is not fully understood in the subjects without HF. Therefore, we assessed the relationship between RV function and exercise capacity, both in patients with HF (HF+) and in patients with heart disease but not developed HF (HF-).

Methods

Two hundred and fifty-two patients with heart disease who underwent both Doppler echocardiography at rest and cardio-pulmonary exercise testing (CPET) for the assessment of heart function were enrolled (HF+: n = 142, HF-: n = 110). We measured left ventricular ejection fraction (LVEF), peak early diastolic transmitral flow velocity (E), peak late diastolic transmitral flow velocity (A), early diastolic mitral annular velocity (e’), left atrial volume (LAV), and tricuspid annular plane systolic excursion (TAPSE) by echocardiography. After echocardiographic examination, symptom-limited exercise testing was performed with simultaneous respiratory gas analysis, and peak oxygen consumption (pVO2) was determined. Blood examination including hemoglobin (Hb) and brain natriuretic peptide (BNP) was done on the same day.

Results

There were significant relationships between pVO2 and LVEF (r = 0.16, p = 0.005), e" (r = 0.51, p < 0.0001), E/e" (r=-0.47, p < 0.0001), LAV (r=-0.21, p = 0.0002), and TAPSE (r = 0.33, p < 0.0001) in the whole subjects. In the multiple regression analyses, age, Hb, E/e" and TAPSE were selected as significant determinants for pVO2 both in HF+ (R²=0.39, p < 0.0001) and HF- (R²=0.33, p < 0.0001).

Conclusion

RV function is the prime determinant of exercise capacity in patients at risk of HF, as well as in patients with HF.

Abstract P743 Figure.

P986Future risk of bradyarrhythmias in patients with hypertrophic cardiomyopathy and implantable cardioverter defibrillator indication

Background

Subcutaneous-implantable cardioverter defibrillator (S-ICD) has been shown to be effective for prevention of sudden cardiac death. Patients with hypertrophic cardiomyopathy (HCM) having ICD indication are considered to introduce either S-ICD or transvenous-ICD, however it is uncertain which is better since S-ICD is not suitable for patients who need pacing and data on the necessity for pacing in HCM patients are limited.

Purpose

The purpose of this study was to investigate the risk factors associated with the future risk of bradyarrhythmias needed to be paced in patients with HCM and ICD indication.

Methods

This is a retrospective, single-center cohort study. Of 169 HCM patients diagnosed in our institution, 80 with ICD indication in accordance with the Japanese guideline in 2011 were enrolled as study subjects (31 females, mean age 63±15 years). They were divided into two groups – patients who progressed to bradyarrhythmias which needed pacing during the follow-up period (Brady group) and those who not (Non-brady group). Baseline characteristics at the time of diagnosis of HCM including demographic information, the results of clinical examination such as blood test, echocardiography and electrocardiography (ECG) were compared between the Brady and Non-brady group.

Results

During a mean follow-up period of 6.8±5.4 years, 9 patients (11%) progressed bradyarrhtyhmias which needed pacing. Symptomatic sick sinus syndrome (SSS) was the primary cause (7 SSS, 1 atrial fibrillation [AF] with bradycardia, 1 after atrioventricular nodal ablation). Comparing between the Brady and Non-brady group, there was no significant difference in clinical variables such as age, heart rate, PR interval and QRS duration in ECG, EF levels, BNP levels, beta-blocker usage rate, prevalence of hypertension or diabetes mellitus. On the other hand, women were more in Brady group than in Non-brady group (7/9, 78% vs. 24/71, 34%; p=0.01). Furthermore, more patients in Brady group had documented AF at the beginning and during follow-up period (7/9, 78% vs. 25/71, 36%; p=0.02) and took anti-arrhythmic drugs (AAD) (8/9, 89% vs. 19/71, 27%; p<0.001) including amiodarone than those in Non-brady group.

Conclusion

In HCM patients with ICD indication, around 10% of patients have a potential risk of bradyarrhythmias needed to be paced, especially in female, those with AF and/or AAD usage.

Population panmixia and demographic expansion of a highly piscivorous marine fish Scomberomorus niphonius

Population structure and demographic history of the Japanese Spanish mackerel Scomberomorus niphonius a highly piscivorous and migratory marine fish, were assessed using mitochondrial DNA control region sequences (n = 720) and microsatellite genotypes at five loci (n = 1331) for samples collected on Japanese coasts from 2001 to 2010. The population structure was panmictic and the haplotype and allele frequencies were temporally stable even during the recent recovery process. Demographic expansion was strongly supported throughout the Pleistocene, suggesting that the oscillating glacial and interglacial climate conditions in the Pleistocene had no substantial impact on the demographic history of S. niphonius.

Validation of a commercial serodiagnostic kit for diagnosing pulmonary Mycobacterium avium complex disease

SETTING

A commercial serodiagnostic kit for diagnosing pulmonary disease due to Mycobacterium avium complex (MAC-PD) was developed and launched in Japan in 2011.

OBJECTIVE

To evaluate the performance of this kit in routine clinical settings.

METHODS

In this retrospective single-centre study, data on serum levels of anti-glycopeptidolipid (GPL) core IgA antibody (U/ml) measured using the kit were analysed in patients diagnosed with MAC-PD according to American Thoracic Society criteria, in those with pulmonary tuberculosis (PTB) or pulmonary M. kansasii disease and in healthy volunteers.

RESULTS

The anti-GPL-core IgA antibody levels of serum were significantly higher (P < 0.0001) in patients with MAC-PD (n = 485) than in those with PTB (n = 133) or pulmonary M. kansasii disease (n = 23) or in healthy subjects (n = 265). When the cut-off level was set at 0.7 U/ml, the sensitivity and specificity were respectively 78.6% and 96.9%. Higher antibody levels were observed in patients with greater extent of disease on chest computed tomography (P < 0.0001).

CONCLUSIONS

The serodiagnostic kit revealed good sensitivity and specificity. The antibody levels may reflect disease activity. Additional work is needed to determine whether the diagnostic assay could be used in conjunction with current diagnostic criteria to improve the diagnosis of MAC-PD.

Small molecule-induced mitochondrial disruption directs prostate cancer inhibition via UPR signaling

We previously identified SMIP004 (N-(4-butyl-2-methyl-phenyl) acetamide) as a novel inducer of cancer-cell selective apoptosis of human prostate cancer cells. SMIP004 decreased the levels of positive cell cycle regulators, upregulated cyclin-dependent kinase inhibitors, and resulted in G1 arrest, inhibition of colony formation in soft agar, and cell death. However, the mechanism of SMIP004-induced cancer cell selective apoptosis remained unknown. Here, we used chemical genomic and proteomic profiling to unravel a SMIP004-induced pro-apoptotic pathway, which initiates with disruption of mitochondrial respiration leading to oxidative stress. This, in turn, activates two pathways, one eliciting cell cycle arrest by rapidly targeting cyclin D1 for proteasomal degradation and driving the transcriptional downregulation of the androgen receptor, and a second pathway that activates pro-apoptotic signaling through MAPK activation downstream of the unfolded protein response (UPR). SMIP004 potently inhibits the growth of prostate and breast cancer xenografts in mice. Our data suggest that SMIP004, by inducing mitochondrial ROS formation, targets specific sensitivities of prostate cancer cells to redox and bioenergetic imbalances that can be exploited in cancer therapy.

Polypeptide N-acetylgalactosaminyl transferase 3 independently predicts high-grade tumours and poor prognosis in patients with renal cell carcinomas

BACKGROUND

The polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) family of enzymes regulates the initial steps of mucin-type O-glycosylation. N-acetylgalactosaminyltransferases might show novel patterns of GalNAc-T glycosylation on tumour-derived proteins, which could influence cancer biology, but its mechanisms are unclear. We investigated the association of GalNAc-T3 and -T6 expressions with clinicopathological features and prognoses of patients with renal cell carcinomas (RCCs).

METHODS

Expressions of GalNAc-T3/6 and cell-adhesion molecules were analysed immunohistochemically in 254 paraffin-embedded tumour samples of patients with RCC.

RESULTS

Of 138 GalNAc-T3+ cases, 46 revealed significant co-expression with GalNAc-T6. N-acetylgalactosaminyltransferases-3+ expression showed a close relationship to poor clinical performance and large tumour size, or pathologically high Fuhrman's grading, and presence of vascular invasion and necrosis. The GalNAc-T3-positivity potentially suppressed adhesive effects with a significantly low β-catenin expression. Univariate and multivariate analyses showed the GalNAc-T3+ group, but not the GalNAc-T6+ group, to have significantly worse survival rates.

CONCLUSION

N-acetylgalactosaminyltransferases-3 expression independently predicts high-grade tumour and poor prognosis in patients with RCC, and may offer a therapeutic target against RCC.

Targeted delivery of paclitaxel to EphA2-expressing cancer cells

PURPOSE

YSA is an EphA2-targeting peptide that effectively delivers anticancer agents to prostate cancer tumors. Here, we report on how we increased the drug-like properties of this delivery system.

EXPERIMENTAL DESIGN

By introducing non-natural amino acids, we have designed two new EphA2 targeting peptides: YNH, where norleucine and homoserine replace the two methionine residues of YSA, and dYNH, where a D-tyrosine replaces the L-tyrosine at the first position of the YNH peptide. We describe the details of the synthesis of YNH and dYNH paclitaxel conjugates (YNH-PTX and dYNH-PTX) and their characterization in cells and in vivo.

RESULTS

dYNH-PTX showed improved stability in mouse serum and significantly reduced tumor size in a prostate cancer xenograft model and also reduced tumor vasculature in a syngeneic orthotopic allograft mouse model of renal cancer compared with vehicle or paclitaxel treatments.

CONCLUSION

This study reveals that targeting EphA2 with dYNH drug conjugates could represent an effective way to deliver anticancer agents to a variety of tumor types.

Long-term radiographic outcome of nodular bronchiectatic Mycobacterium avium complex pulmonary disease

BACKGROUND

Although Mycobacterium avium complex pulmonary disease (MAC-PD) is a growing health problem, little is known about long-term radiographic outcome and factors for deterioration in patients with MAC-PD.

METHODS

Data on patients with nodular bronchiectatic (NBE) MAC-PD who underwent regular follow-up for >5 years were retrospectively reviewed. Changes in plain chest radiograph (CXR) and baseline characteristics were compared between the stable and deteriorated groups.

RESULTS

Seventy-two patients were investigated, including 30 patients who were examined 10 years after the initial visit. One patient (1.4%) showed progressive or remarkably progressive disease on CXR at 1 year; this rate increased to 22.2% at 5 years and to 53.3% at 10 years. Body mass index (BMI) at the initial visit was lower in the deteriorated group than in the stable group. Cavitary disease and resistance to a macrolide were seen more frequently at the initial visit in the deteriorated group than in the stable group.

CONCLUSIONS

NBE MAC-PD is a slowly but substantially progressive long-term infection (5-10 years). Our data suggest that patients with lower BMI, cavitary disease and resistance to a macrolide at initial visit are more likely to progress to deteriorating disease.

An optically pure apogossypolone derivative as potent pan-active inhibitor of anti-apoptotic bcl-2 family proteins

Our focus in the past several years has been on the identification of novel and effective pan-Bcl-2 antagonists. We have recently reported a series of Apogossypolone (ApoG2) derivatives, resulting in the chiral compound (±) BI97D6. We report here the synthesis and evaluation on its optically pure (-) and (+) atropisomers. Compound (-) BI97D6 potently inhibits the binding of BH3 peptides to Bcl-X(L), Bcl-2, Mcl-1, and Bfl-1 with IC(50) values of 76 ± 5, 31 ± 2, 25 ± 8, and 122 ± 28 nM, respectively. In a cellular assay, compound (-) BI97D6 effectively inhibits cell growth in the PC-3 human prostate cancer and H23 human lung cancer cell lines with EC(50) values of 0.22 ± 0.08 and 0.14 ± 0.02 μM, respectively. Similarly, compound (-) BI97D6 effectively induces apoptosis in the BP3 human lymphoma cell line in a dose-dependent manner. The compound also shows little cytotoxicity against bax(-/-)/bak(-/-) cells, suggesting that it kills cancers cells predominantly via a Bcl-2 pathway. Moreover, compound (-) BI97D6 displays in vivo efficacy in both a Bcl-2-transgenic mouse model and in a prostate cancer xenograft model in mice. Therefore, compound (-) BI97D6 represents a promising drug lead for the development of novel apoptosis-based therapies for cancer.

Efficient elimination of cancer cells by deoxyglucose-ABT-263/737 combination therapy

As single agents, ABT-263 and ABT-737 (ABT), molecular antagonists of the Bcl-2 family, bind tightly to Bcl-2, Bcl-xL and Bcl-w, but not to Mcl-1, and induce apoptosis only in limited cell types. The compound 2-deoxyglucose (2DG), in contrast, partially blocks glycolysis, slowing cell growth but rarely causing cell death. Injected into an animal, 2DG accumulates predominantly in tumors but does not harm other tissues. However, when cells that were highly resistant to ABT were pre-treated with 2DG for 3 hours, ABT became a potent inducer of apoptosis, rapidly releasing cytochrome c from the mitochondria and activating caspases at submicromolar concentrations in a Bak/Bax-dependent manner. Bak is normally sequestered in complexes with Mcl-1 and Bcl-xL. 2DG primes cells by interfering with Bak-Mcl-1 association, making it easier for ABT to dissociate Bak from Bcl-xL, freeing Bak to induce apoptosis. A highly active glucose transporter and Bid, as an agent of the mitochondrial apoptotic signal amplification loop, are necessary for efficient apoptosis induction in this system. This combination treatment of cancer-bearing mice was very effective against tumor xenograft from hormone-independent highly metastasized chemo-resistant human prostate cancer cells, suggesting that the combination treatment may provide a safe and effective alternative to genotoxin-based cancer therapies.

Design and characterization of a potent and selective dual ATP- and substrate-competitive subnanomolar bidentate c-Jun N-terminal kinase (JNK) inhibitor

c-Jun N-terminal kinases (JNKs) represent valuable targets in the development of new therapies. Present on the surface of JNK is a binding pocket for substrates and the scaffolding protein JIP1 in close proximity to the ATP binding pocket. We propose that bidentate compounds linking the binding energies of weakly interacting ATP and substrate mimetics could result in potent and selective JNK inhibitors. We describe here a bidentate molecule, 19, designed against JNK. 19 inhibits JNK kinase activity (IC(50) = 18 nM; K(i) = 1.5 nM) and JNK/substrate association in a displacement assay (IC(50) = 46 nM; K(i) = 2 nM). Our data demonstrate that 19 targets for the ATP and substrate-binding sites on JNK concurrently. Finally, compound 19 successfully inhibits JNK in a variety of cell-based experiments, as well as in vivo where it is shown to protect against Jo-2 induced liver damage and improve glucose tolerance in diabetic mice.

Abstract 5: Synthesis and biological evaluation of 5, 5’ substituted apogossypol and apogossypolone derivatives as pan-active inhibitors of anti-apoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins

Overexpression of anti-apoptotic Bcl-2 family proteins is commonly related with tumor maintenance, progression, and chemoresistance. Inhibition of these anti-apoptotic proteins is an attractive approach for cancer therapy. Guided by nuclear magnetic resonance (NMR) binding assays and computational docking studies, a series of 5, 5’ substituted Apogossypol and Apogossypolone derivatives was synthesized and identified pan-active antagonists of anti-apoptotic Bcl-2 family proteins, with binding potency in the low micromolar to nanomolar range. Apogossypol derivative BI97C1 inhibits the binding of BH3 peptides to Bcl-XL, Bcl-2 and Mcl-1 with IC50 values of 0.31, 0.32 and 0.20 µM, respectively. In a cellular assay, BI97C1 potently inhibits cell growth in the H460 human lung cancer and PC-3 human prostate cancer cell lines with EC50 values of 0.40 and 0.13 µM, respectively, and effectively induces apoptosis of the BP3 human lymphoma cell line (EC50 = 0.049 µM) in a dose-dependent manner. Apogossypolone derivative BI97D1 also potently inhibit cell growth in many cancer cell lines. BI97C1 and BI97D1 further display in vivo efficacy in transgenic mice in which Bcl-2 is overexpressed in splenic B-cells and also demonstrated superior single-agent antitumor efficacy in mouse xenograft model and represent promising drug leads for the development of novel apoptosis-based therapies for cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5. doi:10.1158/1538-7445.AM2011-5

Genetic effects of hatchery fish on wild populations in red sea bream Pagrus major (Perciformes, Sparidae) inferred from a partial sequence of mitochondrial DNA

Variation in the mitochondrial DNA transcriptional control region sequence was investigated in wild and hatchery-released red sea bream Pagrus major from Kagoshima Bay, where an extensive hatchery-release programme has been conducted for >30 years. The programme has successfully augmented commercial catches in the bay (released juveniles have been produced from the captive broodstock, repeatedly used over multiple generations). Samples were also obtained from outside the bay, where limited stocking has occurred. Genetic diversity indices measured as number of haplotypes, haplotype richness, haplotype diversity and nucleotide diversity were lower in hatchery-released fish than in wild fish. Genetic differences in wild fish from the bay, especially in the inner bay, compared with fish from outside the bay were detected in terms of decreased genetic diversity indices and changed haplotype frequencies. Unbiased population pair-wise F(ST) estimates based on an empirical Bayesian method, however, revealed low genetic differentiation between samples from the bay and its vicinity. Mixed stock identification analyses estimated the proportion of hatchery-released fish in wild populations in the inner and central bays at 39·0 and 8·7%, respectively, although the precision of the estimates was very low because of the small genetic differentiation between populations and relatively small sample sizes. Hence, the long-term extensive hatchery release programme has affected the genetic diversity of wild populations in the bay; however, the genetic effects were low and appeared to remain within the bay.

Synthesis and biological evaluation of Apogossypolone derivatives as pan-active inhibitors of antiapoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins

Overexpression of antiapoptotic Bcl-2 family proteins is commonly related with tumor maintenance, progression, and chemoresistance. Inhibition of these antiapoptotic proteins is an attractive approach for cancer therapy. Guided by nuclear magnetic resonance (NMR) binding assays, a series of 5,5' substituted compound 6a (Apogossypolone) derivatives was synthesized and identified pan-active antagonists of antiapoptotic Bcl-2 family proteins, with binding potency in the low micromolar to nanomolar range. Compound 6f inhibits the binding of BH3 peptides to Bcl-X(L), Bcl-2, and Mcl-1 with IC(50) values of 3.10, 3.12, and 2.05 μM, respectively. In a cellular assay, 6f potently inhibits cell growth in several human cancer cell lines in a dose-dependent manner. Compound 6f further displays in vivo efficacy in transgenic mice and demonstrated superior single-agent antitumor efficacy in a PPC-1 mouse xenograft model. Together with its negligible toxicity, compound 6f represents a promising drug lead for the development of novel apoptosis-based therapies for cancer.

BI-97C1, an optically pure Apogossypol derivative as pan-active inhibitor of antiapoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins

In our continued attempts to identify novel and effective pan-Bcl-2 antagonists, we have recently reported a series of compound 2 (Apogossypol) derivatives, resulting in the chiral compound 4 (8r). We report here the synthesis and evaluation on its optically pure individual isomers. Compound 11 (BI-97C1), the most potent diastereoisomer of compound 4, inhibits the binding of BH3 peptides to Bcl-X(L), Bcl-2, Mcl-1, and Bfl-1 with IC(50) values of 0.31, 0.32, 0.20, and 0.62 microM, respectively. The compound also potently inhibits cell growth of human prostate cancer, lung cancer, and lymphoma cell lines with EC(50) values of 0.13, 0.56, and 0.049 microM, respectively, and shows little cytotoxicity against bax(-/-)bak(-/-) cells. Compound 11 displays in vivo efficacy in transgenic mice models and also demonstrated superior single-agent antitumor efficacy in a prostate cancer mouse xenograft model. Therefore, compound 11 represents a potential drug lead for the development of novel apoptosis-based therapies against cancer.

A survey of the anti-apoptotic Bcl-2 subfamily expression in cancer types provides a platform to predict the efficacy of Bcl-2 antagonists in cancer therapy

We investigated the mRNA expression levels of all six antiapoptotic Bcl-2 subfamily members in 68 human cancer cell lines using qPCR techniques and measured the ability of known Bcl-2 inhibitors to induce cell death in 36 of the studied tumor cell lines. Our study reveals that Mcl-1 represents the anti-apoptotic Bcl-2 subfamily member with the highest mRNA levels in the lung, prostate, breast, ovarian, renal, and glioma cancer cell lines. In leukemia/lymphoma and melanoma cancer cell lines, Bcl-2 and Bfl-1 had the highest levels of mRNA, respectively. The observed correlation between the cell killing properties of known Bcl-2 inhibitors and the relative mRNA expression levels of anti-apoptotic Bcl-2 proteins provide critical insights into apoptosis-based anticancer strategies that target Bcl-2 proteins. Our data may explain current challenges of selective Bcl-2 inhibitors in the clinic, given that severe expression of Bcl-2 seems to be limited to leukemia cell lines. Furthermore, our data suggest that in most cancer types a strategy targeted to Mcl-1 inhibition, or combination of Bfl-1 and Mcl-1 inhibition for melanoma, may prove to be more successful than therapies targeting only Bcl-2.

Chemical biology strategy reveals pathway-selective inhibitor of NF-kappaB activation induced by protein kinase C

Dysregulation of NF-kappaB activity contributes to many autoimmune and inflammatory diseases. At least nine pathways for NF-kappaB activation have been identified, most of which converge on the IkappaB kinases (IKKs). Although IKKs represent logical targets for potential drug discovery, chemical inhibitors of IKKs suppress all known NF-kappaB activation pathways and thus lack the selectivity required for safe use. A unique NF-kappaB activation pathway is initiated by protein kinase C (PKC) that is stimulated by antigen receptors and many growth factor receptors. Using a cell-based high-throughput screening (HTS) assay and chemical biology strategy, we identified a 2-aminobenzimidazole compound, CID-2858522, which selectively inhibits the NF-kappaB pathway induced by PKC, operating downstream of PKC but upstream of IKKbeta, without inhibiting other NF-kappaB activation pathways. In human B cells stimulated through surface immunoglobulin, CID-2858522 inhibited NF-kappaB DNA-binding activity and expression of endogenous NF-kappaB-dependent target gene, TRAF1. Altogether, as a selective chemical inhibitor of the NF-kappaB pathway induced by PKC, CID-2858522 serves as a powerful research tool and may reveal new paths toward therapeutically useful NF-kappaB inhibitors.

Apogossypol derivatives as pan-active inhibitors of antiapoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins

Guided by nuclear magnetic resonance (NMR) binding assays and computational docking studies, a series of 5,5' substituted apogossypol derivatives was synthesized that resulted in potent pan-active inhibitors of antiapoptotic Bcl-2 family proteins. Compound 8r inhibits the binding of BH3 peptides to Bcl-X(L), Bcl-2, Mcl-1, and Bfl-1 with IC(50) values of 0.76, 0.32, 0.28, and 0.73 microM, respectively. The compound also potently inhibits cell growth of human lung cancer and BP3 human B-cell lymphoma cell lines with EC(50) values of 0.33 and 0.66 microM, respectively. Compound 8r shows little cytotoxicity against bax(-/-)bak(-/-) cells, indicating that it kills cancers cells via the intended mechanism. The compound also displays in vivo efficacy in transgenic mice in which Bcl-2 is overexpressed in splenic B-cells. Together with its improved chemical, plasma, and microsomal stability relative to compound 2 (apogossypol), compound 8r represents a promising drug lead for the development of novel apoptosis-based therapies for cancer.

Apogossypol derivatives as antagonists of antiapoptotic Bcl-2 family proteins

Guided by a combination of nuclear magnetic resonance binding assays and computational docking studies, we synthesized a library of 5,5' substituted Apogossypol derivatives as potent Bcl-XL antagonists. Each compound was subsequently tested for its ability to inhibit Bcl-XL in an in vitro fluorescence polarization competition assay and exert single-agent proapoptotic activity in human cancer cell lines. The most potent compound BI79D10 binds to Bcl-XL, Bcl-2, and Mcl-1 with IC50 values of 190, 360, and 520 nmol/L, respectively, and potently inhibits cell growth in the H460 human lung cancer cell line with an EC50 value of 680 nmol/L, expressing high levels of Bcl-2. BI79D10 also effectively induces apoptosis of the RS11846 human lymphoma cell line in a dose-dependent manner and shows little cytotoxicity against bax-/-bak-/- mouse embryonic fibroblast cells, in which antiapoptotic Bcl-2 family proteins lack a cytoprotective phenotype, implying that BI79D10 has little off-target effects. BI79D10 displays in vivo efficacy in transgenic mice, in which Bcl-2 is overexpressed in splenic B cells. Together with its improved plasma and microsomal stability relative to Apogossypol, BI79D10 represents a lead compound for the development of novel apoptosis-based therapies for cancer.

A short Nur77-derived peptide converts Bcl-2 from a protector to a killer

Bcl-2 can be converted into a proapoptotic molecule by nuclear receptor Nur77. However, the development of Bcl-2 converters as anticancer therapeutics has not been explored. Here we report the identification of a Nur77-derived Bcl-2-converting peptide with 9 amino acids (NuBCP-9) and its enantiomer, which induce apoptosis of cancer cells in vitro and in animals. The apoptotic effect of NuBCPs and their activation of Bax are not inhibited but rather potentiated by Bcl-2. NuBCP-9 and its enantiomer bind to the Bcl-2 loop, which shares the characteristics of structurally adaptable regions with many cancer-associated and signaling proteins. NuBCP-9s act as molecular switches to dislodge the Bcl-2 BH4 domain, exposing its BH3 domain, which in turn blocks the activity of antiapoptotic Bcl-X(L).

Synthesis and evaluation of Apogossypol atropisomers as potential Bcl-xL antagonists

Anti-apoptotic Bcl-2 family proteins such as Bcl-2 and Bcl-X(L) have been recently validated as targets for the discovery of novel anti-cancer agents. We previously reported that racemic (+/-) Apogossypol, a semi-synthetic compound derived from the natural product Gossypol, binds and inhibits Bcl-2 and Bcl-X(L)in vitro and in cell. Given that (+) and (-) Gossypol display different proapoptotic activities, here we report on the synthesis of (+) and (-) Apogossypol and the evaluation of their in vitro and cellular activity.

Gambogic acid is an antagonist of antiapoptotic Bcl-2 family proteins

The natural product gambogic acid (GA) has been reported to have cytotoxic activity against tumor cells in culture and was identified as an active compound in a cell-based high-throughput screening assay for activators of caspases, proteases involved in apoptosis. Using the antiapoptotic Bcl-2 family protein, Bfl-1, as a target for screening of a library of natural products, we identified GA as a competitive inhibitor that displaced BH3 peptides from Bfl-1 in a fluorescence polarization assay. Analysis of competition for BH3 peptide binding revealed that GA inhibits all six human Bcl-2 family proteins to various extents, with Mcl-1 and Bcl-B the most potently inhibited [concentrations required for 50% inhibition (IC(50)), < 1 micromol/L]. Competition for BH3 peptide binding was also confirmed using a time-resolved fluorescence resonance energy transfer assay. GA functionally inhibited the antiapoptotic Bcl-2 family proteins as shown by experiments using isolated mitochondria in which recombinant purified Bcl-2 family proteins suppress SMAC release in vitro, showing that GA neutralizes their suppressive effects on mitochondria in a concentration-dependent manner. GA killed tumor cell lines via an apoptotic mechanism, whereas analogues of GA with greatly reduced potency at BH3 peptide displacement showed little or no cytotoxic activity. However, GA retained cytotoxic activity against bax-/-bak-/- cells in which antiapoptotic Bcl-2 family proteins lack a cytoprotective phenotype, implying that GA also has additional targets that contribute to its cytotoxic mechanism. Altogether, the findings suggest that suppression of antiapoptotic Bcl-2 family proteins may be among the cytotoxic mechanisms by which GA kills tumor cells.

Bcl-B expression in human epithelial and nonepithelial malignancies

PURPOSE

Apoptosis plays an important role in neoplastic processes. Bcl-B is an antiapoptotic Bcl-2 family member, which is known to change its phenotype upon binding to Nur77/TR3. The expression pattern of this protein in human malignancies has not been reported.

EXPERIMENTAL DESIGN

We investigated Bcl-B expression in normal human tissues and several types of human epithelial and nonepithelial malignancy by immunohistochemistry, correlating results with tumor stage, histologic grade, and patient survival.

RESULTS

Bcl-B protein was strongly expressed in all normal plasma cells but found in only 18% of multiple myelomas (n = 133). Bcl-B immunostaining was also present in normal germinal center centroblasts and centrocytes and in approximately half of diffuse large B-cell lymphoma (n = 48) specimens, whereas follicular lymphomas (n = 57) did not contain Bcl-B. In breast (n = 119), prostate (n = 66), gastric (n = 180), and colorectal (n = 106) adenocarcinomas, as well as in non-small cell lung cancers (n = 82), tumor-specific overexpression of Bcl-B was observed. Bcl-B expression was associated with variables of poor prognosis, such as high tumor grade in breast cancer (P = 0.009), microsatellite stability (P = 0.0002), and left-sided anatomic location (P = 0.02) of colorectal cancers, as well as with greater incidence of death from prostate cancer (P = 0.005) and shorter survival of patients with small cell lung cancer (P = 0.009). Conversely, although overexpressed in many gastric cancers, Bcl-B tended to correlate with better outcome (P = 0.01) and more differentiated tumor histology (P < 0.0001).

CONCLUSIONS

Tumor-specific alterations in Bcl-B expression may define subsets of nonepithelial and epithelial neoplasms with distinct clinical behaviors.

Comparison of pharmacokinetic and metabolic profiling among gossypol, apogossypol and apogossypol hexaacetate

PURPOSE

To characterize the stability, pharmacokinetics and metabolism of analogs of gossypol, apogossypol and apogossypol hexaacetate to provide a basis for comparison.

METHODS

Gossypol, apogossypol and apogossypol hexaacetate were incubated in plasma or liver microsomes from various species, or administered to mice, respectively, from which the stability, metabolism and pharmacokinetic profiles of these analogs were quantitatively determined using a liquid chromatography-mass spectrometry (LC/MS/MS) method.

RESULTS

In various species of plasma, apogossypol and gossypol exhibited similar stability, while 20-40% of apogossypol hexaacetate was converted into apogossypol with concurrent formation of the corresponding di-, tri-, tetra-, and penta-acetates of apogossypol. (+/-)-Gossypol and (-)-gossypol showed comparable pharmacokinetic profile and oral bioavailability (12.2-17.6%) with some variations of clearance and V (ss) following oral and intravenous administration to mice. At the same molar dose, apogossypol showed delayed T (max)(1 h), a slower clearance rate and less distribution after administration to mice. Mono- and di-glucuronide conjugates of apogossypol were readily observed in mouse plasma following administration. Apogossypol formulated in sesame oil appeared to possess larger AUC and thus higher oral bioavailability than that formulated in cremophor EL:ethanol:saline. In contrast, intravenous apogossypol hexaacetate exhibited highest clearance rate partially due to its conversion into apogossypol. Concomitant with disappearance of apogossypol hexaacetate (iv), apogossypol converted from apogossypol hexaacetate was quantitatively detected, and accounted for approximately 30% of total plasma apogossypol hexaacetate. Oral apogossypol hexaacetate showed no bioavailability with little apogossypol occurring in the plasma. In human and mouse liver microsomes, glucuronide conjugates of apogossypol and its acetates were readily identified with the exception of gossypol glucuronidation. Apogossypol appeared more stable in human and mouse liver microsomal preparations than gossypol and apogossypol hexaacetate.

CONCLUSIONS

Apogossypol and gossypol show similar oral and intravenous pharmacokinetic profiles and in vitro stability although apogossypol appears to have a slower clearance rate, larger AUC, and better microsomal stability. Apogossypol hexaacetate converts to apogossypol in both in vitro and in vivo settings and lacks any quantifiable oral bioavailability.

Serological test and chest computed tomography findings in patients with Mycobacterium avium complex lung disease

The present authors have previously reported the usefulness of a serodiagnostic test to detect serum glycopeptidolipid (GPL) core antibody in diagnosing Mycobacterium avium complex (MAC) lung disease in immunocompetent patients. The aim of the present study was to investigate correlations between the levels of antibody against GPL core and chest computed tomography (CCT) findings in patients with MAC lung disease. A total of 47 patients with MAC-positive culture from their sputum and who had radiographic abnormalities were investigated. Thirty-three patients met the American Thoracic Society criteria for MAC disease; 14 did not. All patients underwent both CCT examination and the serodiagnostic test for MAC at the same time. Small nodular shadows were seen on CCT in all 47 patients and bronchiectasis shadows were seen in 39 (83%) of them. There was a significant positive correlation between the extent of the disease and the level of GPL core immunoglobulin (Ig)A antibody. The levels of GPL core IgA antibody were significantly elevated in patients who had nodular shadows (10-30 mm) compared with patients who had small nodular shadows (<10 mm). The present results document that the levels of immunoglobulin A antibody against glycopeptidolipid core correlate with the chest computed tomography findings of Mycobacterium avium complex lung disease.

Comprehensive assessment of genetic and molecular features predicting outcome in patients with chronic lymphocytic leukemia: results from the US Intergroup Phase III Trial E2997

PURPOSE

Genomic features including unmutated immunoglobulin variable region heavy chain (IgVH) genes, del(11q22.3), del(17p13.1), and p53 mutations have been reported to predict the clinical course and overall survival of patients with chronic lymphocytic leukemia (CLL). In addition, ZAP-70 and Bcl-2 family proteins have been explored as predictors of outcome.

PATIENTS AND METHODS

We prospectively evaluated the prognostic significance of a comprehensive panel of laboratory factors on both response and progression-free survival (PFS) using samples and data from 235 patients enrolled onto a therapeutic trial. Patients received either fludarabine (FL; n = 113) or fludarabine plus cyclophosphamide (FC; n = 122) as part of a US Intergroup randomized trial for previously untreated CLL patients.

RESULTS

Complete response (CR) rates were 24.6% for patients receiving FC and 5.3% for patients receiving FL (P = .00004). PFS was statistically significantly longer in patients receiving FC (median, 33.5 months for patients receiving FC and 19.9 months for patients receiving FL; P < .0001). The occurrence of del(17p13.1) (hazard ratio, 3.428; P = .0002) or del(11q22.3) (hazard ratio, 1.904; P = .006) was associated with reduced PFS. CR and overall response rates were not significantly different based on cytogenetics, IgVH mutational status, CD38 expression, or p53 mutational status. Expression of ZAP-70, Bcl-2, Bax, Mcl-1, XIAP, Caspase-3, and Traf-1 was not associated with either clinical response or PFS.

CONCLUSION

These results support the use of interphase cytogenetic analysis, but not IgVH, CD38 expression, or ZAP-70 status, to predict outcome of FL-based chemotherapy. Patients with high-risk cytogenetic features should be considered for alternative therapies.

Clinical impact of interstitial pneumonia following surgery for lung cancer

BACKGROUND

Operative morbidity in patients with lung cancer associated with perioperative interstitial pneumonia (IP) has emerged as a serious problem.

PATIENTS AND METHODS

We studied the clinical impact of perioperative related IP in 11 patients (IP group: 7 preoperative known, 4 acute onset) of 473 lung cancer patients who received a pulmonary resection. The IP group was compared to the remaining 462 patients (non-IP group). Demographic data, clinical presentation, and serum KL-6 levels were compared.

RESULTS

There were no differences in age, gender, type of surgery, and pulmonary function except for % DLco between the non-IP and IP groups. The IP group showed a higher in-hospital mortality (n=2: 18.3%) than that of the non-IP group (n=3: 0.6%) (P<0.005). Seven patients with underlying IP with high KL-6 levels showed an uneventful recovery. Two patients with postoperative onset of acute IP had a fatal course associated with elevation of serum KL-6 levels.

CONCLUSIONS

Postoperative development IP is a serious complication with high mortality, and serial measurement of KL-6 levels is useful to assess the activity of IP.

Mechanisms of apoptosis sensitivity and resistance to the BH3 mimetic ABT-737 in acute myeloid leukemia

BCL-2 proteins are critical for cell survival and are overexpressed in many tumors. ABT-737 is a small-molecule BH3 mimetic that exhibits single-agent activity against lymphoma and small-cell lung cancer in preclinical studies. We here report that ABT-737 effectively kills acute myeloid leukemia blast, progenitor, and stem cells without affecting normal hematopoietic cells. ABT-737 induced the disruption of the BCL-2/BAX complex and BAK-dependent but BIM-independent activation of the intrinsic apoptotic pathway. In cells with phosphorylated BCL-2 or increased MCL-1, ABT-737 was inactive. Inhibition of BCL-2 phosphorylation and reduction of MCL-1 expression restored sensitivity to ABT-737. These data suggest that ABT-737 could be a highly effective antileukemia agent when the mechanisms of resistance identified here are considered.

Thymidine-phosphorothioate oligonucleotides induce activation and apoptosis of CLL cells independently of CpG motifs or BCL-2 gene interference

We compared antisense phosphorothioate oligonucleotides (PS-ODN) that target BCL-2 such as Genasense (G3139-PS), with other PS-ODN or phosphodiester-ODN (PO-ODN) in their relative capacity to induce apoptosis of chronic lymphocytic leukemia (CLL) B cells in vitro. Surprisingly, we found that thymidine-containing PS-ODN, but not PO-ODN, induced activation and apoptosis of CLL cells independent of BCL-2 antisense sequence or CpG motifs. All tested thimidine-containing PS-ODN, irrespective of their primary sequences, reduced the expression of Bcl-2 protein and increased the levels of the proapoptotic molecules p53, Bid, Bax in CLL cells. Apoptosis induced by thymidine-containing PS-ODN was preceded by cellular activation, could be blocked by the tyrosine-kinase inhibitor imatinib mesylate (Gleevec), and was dependent on ABL kinase. We conclude that thymidine-containing PS-ODN can activate CLL cells and induce apoptosis via a mechanism that is independent of BCL-2 gene interference or CpG motifs.

Targeting inhibition of K-ras enhances Ad.mda-7-induced growth suppression and apoptosis in mutant K-ras colorectal cancer cells

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a cancer-specific, growth-suppressing and apoptosis-inducing gene with broad-spectrum antitumor activity. However, when administered by means of a replication-incompetent adenovirus, Ad.mda-7, several colorectal carcinoma cell lines are resistant to its antiproliferative and antisurvival effects. We have presently endeavored to determine if K-ras mutations, present in approximately 40-50% of colorectal cancers and which may mediate resistance to chemotherapy and radiotherapy, represent a predisposing genetic factor mitigating reduced sensitivity to Ad.mda-7. To suppress ras expression, three structurally different replication-incompetent adenoviral vectors were engineered that express (1) an intracellular, neutralizing single-chain antibody (scAb) to p21 ras (Ad.K-ras scAb), (2) an antisense (AS) K-ras gene (Ad.K-ras AS) or (3) both mda-7/IL-24 and a K-ras AS gene in a single bipartite virus (Ad.m7.KAS). Simultaneous inhibition of K-ras and expression of mda-7/IL-24 enhanced killing of colorectal carcinoma cells with mutated K-ras, but not with wild-type K-ras. The extent of killing depended on the degree of K-ras downregulation, with Ad.K-ras AS being generally more efficient than Ad.K-ras scAb in combination with Ad.mda-7. These findings support an effective dual-combinatorial approach for the therapy of colorectal cancers that employs a unique cancer-specific suppressor gene (mda-7/IL-24) with targeted inhibition of oncogene (ras) expression.

Select high risk genetic features predict earlier progression following chemotherapy in chronic lymphocytic leukemia: Prospective randomized trial (Intergroup E2997) to evaluate justification for risk-adapted therapy

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Background: Genomic features including lack of IgVH mutations, del(11q), del(17p), and p53 mutations have been reported to predict clinical course and overall survival in CLL patients (pts). Bcl-2 family proteins and ZAP-70 have also been explored as predictors in CLL. Methods: We prospectively evaluated the prognostic significance of clinical features and laboratory variables on response and progression-free survival (PFS) following treatment with fludarabine (F, n=132) or fludarabine plus cyclophosphamide (FC, n=137) as part of the US Intergroup Trial E2997 for previously untreated CLL. Results: FC therapy had higher complete response (CR) (23.4% versus 4.6%), overall response (OR) (74.3% versus 59%), and median PFS (31.6 mos versus 19.2 mos) compared to F. CR and OR were not significantly different based on interphase cytogenetics, IgVH status, or p53 mutation. IgVH status or levels of ZAP-70, Bcl-2, Bax, Mcl-1, XIAP, Caspase-3, and Traf-1 proteins were not associated with clinical response or PFS. IgVH status and ZAP-70 levels were associated with time from diagnosis to treatment. Using a model including treatment arm, pts with del(17p) or (11q) had significantly shorter PFS (hazard ratios 3.54 and 2.05 respectively). In pts with a p53 mutation without del(17p) there was no enhancement of the model predicting poorer outcome, nor did IgVH status enter the model for predicting PFS. Conclusions: Combination chemotherapy is associated with a higher CR, OR, and PFS. Also, initiation of therapy for pts with Rai stages 0/1 resulted in a higher response rate. Del(17p) and del(11q) are highly predictive of shortened PFS with fludarabine-based chemotherapy. IgVH and p53 mutational status, as well as expression of ZAP-70, Bcl-2 family proteins, and CD38, did not predict response or PFS. ZAP-70 expression is associated with cytogenetic subsets predicted to have a worse overall prognosis, but did not identify pts who will do poorly with therapy. A combination of clinical staging and cytogenetics provide support for future risk-stratified treatment of CLL. Pts with a projected short response duration can be identified for future investigational strategies.

No significant financial relationships to disclose.

Ionizing radiation enhances therapeutic activity of mda-7/IL-24: overcoming radiation- and mda-7/IL-24-resistance in prostate cancer cells overexpressing the antiapoptotic proteins bcl-xL or bcl-2

Subtraction hybridization applied to terminally differentiating human melanoma cells identified mda-7/IL-24, a cytokine belonging to the IL-10 gene superfamily. Adenoviral-mediated delivery of mda-7/IL-24 (Ad.mda-7) provokes apoptosis selectively in a wide spectrum of cancers in vitro in cell culture, in vivo in human tumor xenograft animal models and in patients with advanced carcinomas and melanomas. In human prostate cancer cells, a role for mitochondrial dysfunction and induction of reactive oxygen species in the apoptotic process has been established. Ectopic overexpression of bcl-xL and bcl-2 prevents these changes including apoptosis induction in prostate tumor cells by Ad.mda-7. We now document that this resistance to apoptosis can be reversed by treating bcl-2 family overexpressing prostate tumor cells with ionizing radiation in combination with Ad.mda-7 or purified GST-MDA-7 protein. Additionally, radiation augments apoptosis induction by mda-7/IL-24 in parental and neomycin-resistant prostate tumor cells. Radiosensitization to mda-7/IL-24 is dependent on JNK signaling, as treatment with the JNK 1/2/3 inhibitor SP600125 abolishes this effect. Considering that elevated expression of bcl-xL and bcl-2 are frequent events in prostate cancer development and progression, the present studies support the use of ionizing radiation in combination with mda-7/IL-24 as a means of augmenting the therapeutic benefit of this gene in prostate cancer, particularly in the context of tumors displaying resistance to radiation therapy owing to bcl-2 family member overexpression.

An inhibitor of Bcl-2 family proteins induces regression of solid tumours

Proteins in the Bcl-2 family are central regulators of programmed cell death, and members that inhibit apoptosis, such as Bcl-X(L) and Bcl-2, are overexpressed in many cancers and contribute to tumour initiation, progression and resistance to therapy. Bcl-X(L) expression correlates with chemo-resistance of tumour cell lines, and reductions in Bcl-2 increase sensitivity to anticancer drugs and enhance in vivo survival. The development of inhibitors of these proteins as potential anti-cancer therapeutics has been previously explored, but obtaining potent small-molecule inhibitors has proved difficult owing to the necessity of targeting a protein-protein interaction. Here, using nuclear magnetic resonance (NMR)-based screening, parallel synthesis and structure-based design, we have discovered ABT-737, a small-molecule inhibitor of the anti-apoptotic proteins Bcl-2, Bcl-X(L) and Bcl-w, with an affinity two to three orders of magnitude more potent than previously reported compounds. Mechanistic studies reveal that ABT-737 does not directly initiate the apoptotic process, but enhances the effects of death signals, displaying synergistic cytotoxicity with chemotherapeutics and radiation. ABT-737 exhibits single-agent-mechanism-based killing of cells from lymphoma and small-cell lung carcinoma lines, as well as primary patient-derived cells, and in animal models, ABT-737 improves survival, causes regression of established tumours, and produces cures in a high percentage of the mice.

Nurselike cells express BAFF and APRIL, which can promote survival of chronic lymphocytic leukemia cells via a paracrine pathway distinct from that of SDF-1alpha

We examined expression of B cell-activating factor of the tumor necrosis factor (TNF) family (BAFF) and a proliferation-inducing ligand (APRIL) on chronic lymphocytic leukemia (CLL) B cells and nurselike cells (NLCs), which differentiate from CD14+ cells when cultured with CLL B cells. NLCs expressed significantly higher levels of APRIL than monocytes and significantly higher levels of BAFF and APRIL than CLL B cells. Also, the viability of CLL B cells cultured with NLCs was significantly reduced when CLL B cells were cultured with decoy receptor of B-cell maturation antigen (BCMA), which can bind both BAFF and APRIL, but not with BAFF receptor:Fc (BAFF-R:Fc), which binds only to BAFF. The effect(s) of BAFF or APRIL on leukemia cell survival appeared additive and distinct from that of stromal cell-derived factor-1alpha (SDF-1alpha), which in contrast to BAFF or APRIL induced leukemia cell phosphorylation of p44/42 mitogen-activated protein kinase (extracellular signal-regulated kinase-1/2 [ERK1/2]) and AKT. Conversely, BAFF and APRIL, but not SDF-1alpha, induced CLL-cell activation of the nuclear factor-kappaB1 (NF-kappaB1) and enhanced CLL-cell expression of the antiapoptotic protein Mcl-1. However, BAFF, but not APRIL, also induced CLL-cell activation of NF-kappaB2. We conclude that BAFF and APRIL from NLCs can function in a paracrine manner to support leukemia cell survival via mechanisms that are distinct from those of SDF-1alpha, indicating that NLCs use multiple distinct pathways to support CLL-cell survival.

Rational design and real time, in-cell detection of the proapoptotic activity of a novel compound targeting Bcl-X(L)

Antiapoptotic Bcl-2-family proteins Bcl-2 and Bcl-X(L) have been recently validated as drug discovery targets for cancer. Here, by using a combination of molecular modeling, NMR-based structural analysis, fluorescence polarization assays, and cell-based assays, we have designed and characterized a novel proapoptotic compound targeting these proteins. Our compound, Apogossypol, is capable of binding and inhibiting Bcl-2 and Bcl-X(L) with high affinity and induces apoptosis of tumor cell lines. Mechanistic studies on the action of our compound were also performed via confocal microscopy that provided real-time detection of the interaction with Bcl-X(L) in intact cells. Finally, preliminary data on cells freshly isolated from patients affected by chronic lymphocytic leukemia strongly suggest potential applications of Bcl-2 antagonists as chemosensitizers in cancer therapy.

Liquid chromatography/mass spectrometry analysis of small-scale glycopeptidolipid preparations to identify serovars of Mycobacterium avium-intracellulare complex

AIMS

The antigenic glycopeptidolipids (GPLs) from Mycobacterium avium-intracellulare complex (MAC) are grouped into 28 serovars on the basis of the variable oligosaccharide sequences and the core structures. To facilitate the identification of MAC serovars by employing liquid chromatography/mass spectrometry (LC/MS), the diversity in fatty acyl moieties and the number of acetyl groups of GPLs should be characterized.

METHODS AND RESULTS

Employing a small-scale preparation method, sufficient quantities of intact GPLs could be obtained from several colonies of MAC within 4 h. Tandem mass spectrometry of GPLs showed the presence of common fragment ion at m/z 1048 in the main molecular species of all reference strains. It revealed that the acyl moieties had similar diversity among all serovars. Furthermore, intact GPLs had mainly one or two acetyl groups. This allowed us to determine the masses of each serovar based on intact GPLs and to classify 16 isolates from patients by LC/MS.

CONCLUSIONS

The present serotyping method using LC/MS analysis improved the precision of measurements and shortened the procedure time compared with conventional thin-layer chromatography or the seroagglutination test method.

SIGNIFICANCE AND IMPACT OF THE STUDY

This proposed method proves useful for identifying serovars of MAC for epidemiological and pathogenic research purposes.

BI-1 Regulates an Apoptosis Pathway Linked to Endoplasmic Reticulum Stress

Bax inhibitor-1 (BI-1) is an evolutionarily conserved endoplasmic reticulum (ER) protein that suppresses cell death in both animal and plant cells. We characterized mice in which the bi-1 gene was ablated. Cells from BI-1-deficient mice, including fibroblasts, hepatocytes, and neurons, display selective hypersensitivity to apoptosis induced by ER stress agents (thapsigargin, tunicamycin, brefeldin A), but not to stimulators of mitochondrial or TNF/Fas-death receptor apoptosis pathways. Conversely, BI-1 overexpression protects against apoptosis induced by ER stress. BI-1-mediated protection from apoptosis induced by ER stress correlated with inhibition of Bax activation and translocation to mitochondria, preservation of mitochondrial membrane potential, and suppression of caspase activation. BI-1 overexpression also reduces releasable Ca(2+) from the ER. In vivo, bi-1(-/-) mice exhibit increased sensitivity to tissue damage induced by stimuli that trigger ER stress, including stroke and tunicamycin injection. Thus, BI-1 regulates a cell death pathway important for cytopreservation during ER stress.

The histone deacetylase inhibitor MS-275 induces caspase-dependent apoptosis in B-cell chronic lymphocytic leukemia cells

MS-275 is a histone deacetylase (HDAC) inhibitor that has been reported to mediate its cytotoxic effect through generation of reactive oxygen species (ROS) in proliferating hematopoietic cell lines. We examined efficacy of MS-275 in nonproliferating chronic lymphocytic leukemia (CLL) cells from patients. In these cells, MS-275 demonstrated an in vitro LC(50) that was one log lower than for normal mononuclear cells. Following MS-275 treatment, histones H3 and H4 showed increased acetylation and HDAC enzymatic activity was reduced. Caspase-8, -9, and -3 were activated, and caspase substrates PARP and BID were cleaved. Additionally, FLICE-inhibitory protein (FLIP) was downmodulated following MS-275 incubation. MS-275 treatment caused detectable ROS generation after 15 h of incubation, which was blocked by the caspase inhibitor Z-VAD-fmk. Overexpression of Bcl-2 protein protected against MS-275-induced apoptosis. These data demonstrate that MS-275 is a promising therapy for the treatment of CLL, but that in contrast to previous reports, ROS generation does not precede commitment to apoptosis. Similar to many other therapeutic targets, MS-275-mediated apoptosis is reduced by overexpression of Bcl-2, justifying strategies to combine HDAC inhibitors with Bcl-2 antagonists.

Small-molecule antagonists of apoptosis suppressor XIAP exhibit broad antitumor activity

Apoptosis resistance commonly occurs in cancers, preventing activation of Caspase family cell death proteases. XIAP is an endogenous inhibitor of Caspases overexpressed in many cancers. We developed an enzyme derepression assay, based on overcoming XIAP-mediated suppression of Caspase-3, and screened mixture-based combinatorial chemical libraries for compounds that reversed XIAP-mediated inhibition of Caspase-3, identifying a class of polyphenylureas with XIAP-inhibitory activity. These compounds, but not inactive structural analogs, stimulated increases in Caspase activity, directly induced apoptosis of many types of tumor cell lines in culture, and sensitized cancer cells to chemotherapeutic drugs. Active compounds also suppressed growth of established tumors in xenograft models in mice, while displaying little toxicity to normal tissues. These findings validate IAPs as targets for cancer drug discovery.

Bcl-2 and Bcl-x(L) differentially protect human prostate cancer cells from induction of apoptosis by melanoma differentiation associated gene-7, mda-7/IL-24

Subtraction hybridization identified melanoma differentiation associated gene-7, mda-7, in the context of terminally differentiated human melanoma cells. Based on its structure, cytokine-like properties and proposed mode of action, mda-7 has now been classified as IL-24. When expressed by means of a replication-incompetent adenovirus, Ad.mda-7 induces apoptosis in a broad range of cancer cells, without inducing harmful effects in normal fibroblast or epithelial cells. These unique properties of mda-7/IL-24 suggest that this gene will prove beneficial for cancer gene therapy. We now demonstrate that Ad.mda-7 decreases viability by induction of apoptosis in hormone-responsive (LNCaP) and hormone-independent (DU-145 and PC-3) human prostate carcinomas, without altering growth or survival in early-passage normal human prostate epithelial cells (HuPEC). Ad.mda-7 causes G(2)/M arrest and apoptosis in LNCaP (p53-wildtype), DU-145 (p53 mutant, Bax-negative) and PC-3 (p53-negative) prostate carcinomas, but not in HuPEC. Apoptosis induction correlated with changes in the ratio of pro- to antiapoptotic Bcl-2 protein family members. A potential functional role for changes in bcl-2 family gene expression in Ad.mda-7-induced apoptosis was suggested by the finding that forced overexpression of bcl-x(L) or bcl-2 differentially diminished the apoptotic effect of Ad.mda-7 in prostate carcinomas. These results confirm that induction of apoptosis by the mda-7/IL-24 gene in prostate cancer cells is Bax- and p53-independent and is mediated by mitochondrial pathways involving bcl-2 family gene members. The mda-7/IL-24 gene represents a new class of cancer-specific apoptosis-inducing genes with obvious potential for the targeted gene-based therapy of human prostate cancer.

Cancer prevention by tea polyphenols is linked to their direct inhibition of antiapoptotic Bcl-2-family proteins

Epidemiological data and in vitro studies on cancer chemoprevention by tea polyphenols have gained attention recently from the scientific community, nutritionists, the pharmaceutical industry, and the public. Despite the several efforts made recently to elucidate the molecular basis for the anticancer activity of these natural products, little correlation has been found thus far between the putative protein targets of compounds found in tea extracts and levels found in plasma after tea consumption. Here, by using a combination of nuclear magnetic resonance binding assays, fluorescence polarization assay, and computational docking studies, we found that certain green tea catechins and black tea theaflavins are very potent inhibitors (K(i) in the nanomolar range) of the antiapoptotic Bcl-2-family proteins, Bcl-x(L) and Bcl-2. These data suggest a strong link between the anticancer activities of these tea polyphenols and their inhibition of a crucial antiapoptotic pathway, which is implicated in the development of many human malignancies.

Melanoma differentiation associated gene-7, mda-7/interleukin-24, induces apoptosis in prostate cancer cells by promoting mitochondrial dysfunction and inducing reactive oxygen species

Mda-7/IL-24 (Ad.mda-7) is a novel cytokine gene belonging to the interleukin (IL) 10 gene superfamily. Adenoviral-mediated delivery of mda-7/IL-24 causes growth suppression and apoptosis in a wide spectrum of cancer cells, including prostate, without harming normal cells. We now demonstrate that Ad.mda-7 selectively induces apoptosis in prostate cancer cells by promoting mitochondrial dysfunction and reactive oxygen species (ROS) production. Antioxidants (N-acetyl-L-cysteine and Tiron) and inhibitors of mitochondrial permeability transition (cyclosporine A and bongkrekic acid) inhibit Ad.mda-7-induced mitochondrial dysfunction and apoptosis. Conversely, agents augmenting ROS production (arsenic trioxide, NSC656240, and PK11195) facilitate Ad.mda-7-induced apoptosis. Ectopic expression of Bcl-2 and Bcl-x(L) inhibits mitochondrial changes, ROS production, and apoptosis providing additional support for an association between mitochondrial dysfunction and Ad.mda-7 action. These studies present definitive evidence that changes in mitochondrial function and ROS production are key components associated with selective killing of prostate cancer cells by mda-7/IL-24.

Febrile ulceronecrotic Mucha-Habermann disease: a case report and a review of the literature

This report describes the case of a 76 year old man who suffered from febrile ulceronecrotic Mucha-Habermann disease (FUMHD). Despite this patient's typical clinical and histological findings, the fulminating course led to death. Polymerase chain reaction (PCR) analysis of the skin lesions showed that the infiltrating cells were monoclonal in origin and were from an aberrant clone. FUMHD is a very rare, febrile variant type of pityriasis lichenoides et varioliformis acuta, and is characterised by necrotic cutaneous ulcerations associated with high fever and systemic manifestations. Including this present case, only 18 cases of FUMHD have been reported. FUMHD can occur in both adults and children, although there are several differences between the manifestations of the disease in the two groups. One major difference is prognosis: all cases resulting in fatality are of the adult type, whereas no fatal cases have been reported among children. The aberrant clone detected by PCR may be responsible for host responses, resulting in the severe symptoms observed in this disorder.

Synthetic triterpenoids activate a pathway for apoptosis in AML cells involving downregulation of FLIP and sensitization to TRAIL

Acute myelogenous leukemia (AML) remains a deadly disease for most adult patients, due primarily to the emergence of chemoresistant cells. Defects in apoptosis pathways make important contributions to chemoresistance, suggesting a need to restore apoptosis sensitivity or to identify alternative pathways for apoptosis induction. Triterpenoids represent a class of naturally occurring and synthetic compounds with demonstrated antitumor activity, including 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) and its methyl ester (CDDO-m). We explored the effects of CDDO and CDDO-m in vitro on established AML cell lines (HL-60, U937, AML-2) and on freshly isolated AML blasts. CDDO and CDDO-m reduced the viability of all AML cell lines tested in a dose-dependent manner, with effective doses for killing 50% of cells (ED(50)) within 48 h of approximately 1 and 0.5 muM, respectively. CDDO or CDDO-m also induced substantial increases in cell death in five out of 10 samples of primary AML blasts. Cell death induced by CDDO and CDDO-m was attributed to apoptosis, based on characteristic cell morphology and evidence of caspase activation. Immunoblot analysis demonstrated proteolytic processing of caspase-3, -7, and -8, but not caspase-9, suggesting the involvement of the 'extrinsic' pathway, linked to apoptosis induction by TNF-family death receptors. Accordingly, CDDO and CDDO-m induced concentration-dependent reductions in the levels of FLIP protein, an endogenous antagonist of caspase-8, without altering the levels of several other apoptosis-relevant proteins. Reductions in FLIP were rapid, detectable within 3 h after exposure of AML cell lines to CDDO or CDDO-m. CDDO and CDDO-m also sensitized two of four leukemia lines to TRAIL, a TNF-family death ligand. The findings suggest that synthetic triterpenoids warrant further investigation in the treatment of AML, alone or in combination with TRAIL or other immune-based therapies.

Discovery, characterization, and structure-activity relationships studies of proapoptotic polyphenols targeting B-cell lymphocyte/leukemia-2 proteins

Among the most promising chemopreventive agents, certain natural polyphenols have recently received a great deal of attention because of their demonstrated inhibitory activity against tumorigenesis. In view of their anticancer properties, these compounds also hold great promise as potential chemotherapeutic agents. However, to translate these chemopreventive agents into chemotherapeutic compounds, their exact mechanisms of action must be delineated. By using a multidisciplinary approach guided by modern nuclear magnetic resonance spectroscopy techniques, fluorescence polarization displacement assays, and cell-based assays, we have begun to unravel the mechanisms of actions of certain polyphenols such as Gossypol (a compound from cotton seed extracts) and Purpurogallin (a natural compound extracted from Quercus sp. nutgall) and their derivatives. Our findings suggest that these natural products bind and antagonize the antiapoptotic effects of B-cell lymphocyte/leukemia-2 (Bcl-2) family proteins such as Bcl-x(L). Our in vitro and in vivo data not only open a window of opportunities for the development of novel cancer treatments with these compounds but also provide structural information that can be used for the design and development of novel and more effective analogues.

Depsipeptide (FR901228) induces histone acetylation and inhibition of histone deacetylase in chronic lymphocytic leukemia cells concurrent with activation of caspase 8-mediated apoptosis and down-regulation of c-FLIP protein

Depsipeptide is in clinical trials for chronic lymphocytic leukemia (CLL) on the basis of earlier observations demonstrating selective in vitro activity in CLL. We sought to determine the relationship of histone H3 and H4 acetylation, inhibition of histone deacetylase, and apoptosis observed in CLL cells to justify a pharmacodynamic end point in these clinical trials. We demonstrate that in vitro depsipeptide induces histone H3 and H4 acetylation and histone deacetylase enzyme inhibition at concentrations corresponding to the LC50 (concentration producing 50% cell death) for cultured CLL cells (0.038 microM depsipeptide). The changes in histone acetylation are lysine specific, involving H4 K5, H4 K12, and H3 K9, and to a lesser extent H4 K8, but not H4 K16 or H3 K14. Depsipeptide-induced apoptosis is caspase dependent, selectively involving the tumor necrosis factor (TNF) receptor (extrinsic pathway) initiating caspase 8 and effector caspase 3. Activation of caspase 8 was accompanied by the down-regulation of cellular FLICE-inhibitory protein (c-FLIP, I-FLICE) without evidence of Fas (CD95) up-regulation. Changes in other apoptotic proteins, including Bcl-2, Bax, Mcl-1, and X-linked inhibitor of apoptosis (XIAP), were not observed. Our results demonstrate a relationship between target enzyme inhibition of histone deacetylase, histone H3 and H4 acetylation, and apoptosis involving the TNF-receptor pathway of apoptosis that is not used by other therapeutic agents in CLL. These data suggest use of histone H3 and H4 acetylation, inhibition of histone deacetylase, and down-regulation of FLIP as pharmacodynamic end points for further evaluation of this drug in patients.